Improvement in dove-tail mabkers



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JoHNnVANs, or' PHILADELPHIA, PENNSYLVANIAfAssieuon To HIMSELF AND THOMAS u. sumar,l or SAME PLAGE.

Laim Paten: No. 77,018, dated April 21, 186s.

IMPROVEMENT IN DOVE-TAIL MARKERS.

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TO ALL' WHOM 'IT MAY-CONGERN:

Beit known that I, Jole-IN EVANS, of Philadelphia, Pennsylvania, have invented an Instrument wherewth to Mark Dove-Tails andv I do hereby declare the following to be a full, clear, and exact description of the same. My inventioncons'ists of an instrument, fully described hereafter, for facilitating the marking o f dovettails on one board, and mortises for receiving the said dove-tails on anotherrboard, the instrument being such that when adjusted for marking the dove-tails, it is in a' proper condition to determine the relative position of the mortises. i l

In order-to enable others familiar with mechanism of this class to make and use myl invention, I will now proceed t'o describe the mode of constructing, and using the same, reference being had to the accompanying drawing, which forms a part of this specification, and in which- Figure 1 is a perspective view 'of my instrument for marking dove-tailsr Figure 2, a front view, partly in section. l Figure 3, a plan View. A l Figure 4, a transverse section on'the line 1 2, iig. 2; and Figures 5 and 6, views to illustrate the mode of using the instrument, Similar-letters refer to similar parts throughout the several views. The frame, A, of the instrument consists of two plates, a and a', situated at right angles to each other, and

.made in one piece.

In the plate a is an elongated opening, b, in which a cross-bar, d, is arranged to slide Ato and fro freely, the

.bar being attached to a rod, e, passing through a projection, f, provided with a set-screw, la, for securing the vbar after adjustment.`v

The frame A is cut away near one end for the reception of a slide, B, composed of two plates, z and z", arranged at right angles4 to each other, and made inone. piece, the plate'z' being in the same plane with the platea of the frame, and the plate vf in the same plane with the plate .a of the frame.

The lower edge of the plate z' of the slide is grooved to receive guiding-pins, j y', in the frame, as seen in Hg. 2, and the plate i of. the slide is guided in a similar manner. l v

A lip, c, on the slide, overhangsi the frame, and through a longitudinal slot in this lip passes a set-screw, m, into the'frame, so that the slide an be secured after adjustment. l I

In using the instrument, the slide is adjusted to a'proper position to niark a dove-tail of the desired size. It is then Aplaced on theboard, g. 5, the plate a resting on the surface of the hoard, and the plate a against the edge of the same. The rst dove-tail, 2, is then marked on the top and edge'of the board with a pencil or knife, guided by and following the edges, x'and rc', of the frame, and the edges, y' and y', of the slide, g. 1. After this, the instrument is moved in the direction of the arrow, iig. 5, to a point where it is desired to mark the next dove-tail, 3, after marking which, and before the instrument is removed, the eross-bar, d, is so-adjusted that its front edge will coincide with the line t of the dove-tail 2, when the edge, x', of the instrument is coini cident with the line w of the dovetailS, then the cross-bar is secured so asto serve as a guide in marking the remaining dovetails,-for when the instrument is uiovedr along 'the' edge of the board'until the bar d coincides with the line lu; ofthe dove-tail 3, it isa certain indication that the instrument is in a proper positionfor making the third dove-tail, 4. A 1 v By the aid of the same instrument, with its stop unchanged, the mortises for the reception of these dovetails are'marked on the board, iig. 6, in a mannerwhich will be readily understood, the bar, previously adjusted for the dove-tails, vdetermining the proper distance apart of the mprtises for receivingthese dove-tails 'I claim as my invention, and desire to secure by I'Jetters-PatentW l 1. The within-dclscribed instrument, consisting of Vthe frame A, with its marking-edges x and zr', and theV slide B, with its marking-edges y and y,the whole being constructed, arranged, and operating'substantially as und for the purpose herein set forth. v v

2. The combination of the above with .In testimony whereof, I have Signed my name to the adjstnlile plate d.

this specification in the presence of two subscribing wituessesi JOHN EVANS',v

Witnesses:

JOHN WHITE, C. B. PRIGE; 

